Meet Paul Ryan: a young, smart and energetic face of the Republican Party. Mitt Romney shook up his campaign by picking the Wisconsin congressman as his running mate. The next three months will determine if it was the right decision and with that in mind, here are some things to consider:

1Youth. He's 42 and provides a youthful image for the Republican Party.

2Conservative appeal. Ryan is a hero to conservative activists for his bold plan to cut government. He will energize the GOP base that was more excited about defeating President Barack Obama than embracing Romney.

3Down to earth. Ryan comes across as earnest and substantive and has a touching personal story: his father died of a heart attack when he was teenager. He could add warmth and sincerity that Romney lacks.

Three liabilities

1 The Ryan budget. His proposal would convert Medicare into a subsidy toward the purchase of private health insurance. While that may shore up the long-term viability of Medicare, it's a scary proposition to many older voters. Even if Romney does not adopt the plan wholesale, Democrats will push to make this a central issue.

2Inexperience. Sure, Ryan has been in Congress since 1999. But he lacks the outside government experience Romney says is vital. He also comes up short on foreign policy experience and national security.

3 Bush era. Ryan voted for the bank bailout and a Medicare prescription drug benefit spearheaded by President George W. Bush — both of which are now anathema to tea party conservatives.

Three questions

1Are Americans ready to embrace the sweeping changes Romney and Ryan say are needed to fix the country? Bold makes for good campaign slogans but putting words into action is harder (see: Obamacare).

2Can Ryan do more than excite the GOP base? Can he appeal to Hispanics, women and independent voters? Romney has struggled particularly among Hispanics and Ryan does not seem to help.

3Can Ryan, who is little known outside Wisconsin or Washington, D.C., withstand the national scrutiny that comes with a presidential campaign? He is untested in a national campaign, and his voting history is already being scoured by Democrats.